The present invention relates to an apparatus for aligning lumber, especially blocks from which the first pair of cants has been removed, the alignment of the lumber taking place before feeding it into a saw mill. The apparatus comprises a conveyor for outlining the sawed surface and the profile of the cant-removed blocks. Such a method is a microprocessor or other equivalent calculating unit for processing the measuring data and for controlling the aligning members.
In the prior art, is known for example a method is known for example for aligning cant-removed blocks before feeding them into a saw mill, presented in the Finnish Patent Application No. 761401. According to this method, the cant-removed blocks are centralized symmetrically with respect to the infeed line, while the blocks are in continuous longitudinal movement. The centralizing is arranged to take place by means of centralizing members, which affect two points at the sides of the cant-removed block. Simultaneously the form of the block is outlined by means of a measuring apparatus connected to a calculator. After the measuring, direction of the block is corrected according to the reading obtained from the calculator.
Among the drawbacks of the aforementioned method is the fact that the aligning of the cant-removed blocks takes place on the uneven, unsawed surfaces. Although the purpose is to carry out the centralizing and the alignment at the same points, the unevenness of the surface easily causes errors. One attempt to avoid this drawback in a preferred embodiment of the above mentioned Finnish Patent Application is an arrangement where the centralizing and the aligning members move along with the block. This, however, leads to complex and expensive constructions.